1. Field of the Invention
The present invention relates to a wiring structure of a flexure attached to a head suspension arranged in, for example, a hard disk drive.
2. Description of Related Art
A hard disk drive incorporates a hard disk and a head suspension that supports a head. The hard disk in the hard disk drive is rotated at high speed and the head of the head suspension slightly floats from the surface of the hard disk, to write and read data to and from the hard disk. The head of the head suspension is attached to a flexure that is fitted to and extending along the head suspension. The flexure includes wiring for transmitting write and read signals to and from the head.
Recent hard disk drives are required to have increased capacity, high transfer speed, and reduced power consumption. To meet the requirements, the wiring of the flexure in the hard disk drive is required to improve electric characteristics, such as reducing impedance and inductance, realizing impedance matching with a preamplifier, and preventing attenuation.
To meet the requirements for the wiring of the flexure, Japanese Unexamined Patent Application Publication No. H10-24837 discloses an interleaved wiring technique of alternating a plurality of traces of both polarities in a width direction of the flexure. This technique is capable of reducing the impedance and the like of the wiring of the flexure.
The interleaved wiring, however, causes partial dips or drops in the frequency characteristic of signal transmission loss (hereinafter sometimes referred to as “loss-to-frequency characteristic”) of the wiring, which is not observed in standard wiring employing no interleaved wiring technique. If occur, the partial dips in the loss-to-frequency characteristic cause problems such as creating an unwanted filter and narrowing a bandwidth.